[unreadable] Congenital hyperinsulinism (CHI) is a rare condition that affects approximately 1 in 500,000 infants in the United States. The total prevalence has been estimated to be less than 200,000. Treatment of this disease necessitates surgical removal of the pancreas to control hyperglycemia. Infants with focal lesions are potentially curable by local resection. There are no currently available methods for identifying these focal lesions prior to surgery. [unreadable] [unreadable] A preliminary study being conducted at the applicant's institution suggests that positron emission tomography (PET) with 18F-labeled L-fluoro-dihydroxyphenylalanine (F-DOPA) is useful for identifying and localizing focal lesions. Imaging with F-DOPA will enable selection of surgical approach in children with hyperinsulinism. The applicant's proposal investigates the utility of F-DOPA PET as a noninvasive tool to guide biopsy and nature of pancreatectomy (total versus lesion resection) with focal forms of congenital hyperinsulinism. It is proposed that this study will contribute to the approval of F-DOPA PET for use in image-guided biopsy and pancreatectomy of children with congenital hyperinsulinism, thereby improving the outcome for children with this orphan disease. [unreadable] [unreadable] [unreadable]